I've never shot IDPA, but the Beretta was the first gun I've ever shot in USPSA other than a 1911. I was nervous about the first shot, but to be honest I don't ever recall the difference on the first shot in the couple of matches I shot with the Beretta. I used the 92 to see if I could get used to the DA first pull on a CZ, and I proved to myself that I could.
Think about the fact that on many stages you'll face, your first shot will be a relatively close shot. Most of the ones I can recall the first shot is within 10 yards. Not always, but often enough that even if you pull the first shot slightly, it's not going to make much difference.
I'd say do it. The Beretta is an accurate gun, comfortable to shoot, and low recoil. Not much downside other than that first shot. Plus the decocker allows you to start in Production or SSP without the fear of an AD like the CZ shooters have.